Device for the wireless transmission of a trigger signal

ABSTRACT

A device for wireless transmission of a deployment signal. The device includes two processors on both the primary side and the secondary side, which exchange data with one another. A high degree of redundancy is thereby achieved. The wireless transmission is preferably carried out as inductive transmission.

FIELD OF THE INVENTION

The present invention is directed to a device for wireless transmissionof a deployment signal.

BACKGROUND INFORMATION

German Patent Application No. DE 100 46 695 describes a device forwireless transmission of a deployment signal, which transmits thedeployment signal over a first path and a redundance signal for thedeployment signal over a second path. Deployment then occurs on thesecondary side only if both the deployment signal and the redundancesignal are recognized on the secondary side.

SUMMARY

An example device according to the present invention for wirelesstransmission of a deployment signal may have the advantage over therelated art that there are two processors on both the primary side andthe secondary side, these processors being configured in such a way thatthey exchange data with one another. A high degree of redundancy is thusachieved on the primary and secondary sides, resulting in reliabledeployment of the restraining means such as an airbag or a seat belttightener. The redundance signal and the deployment signal may beanalyzed separately.

It may be particularly advantageous if the primary side is situated in asteering column and the secondary side is situated in the steeringwheel. The device according to the present invention is then suitablefor wireless transmission of a deployment signal for an airbag in asteering wheel.

It may be furthermore advantageous if the primary side is situated inthe vehicle chassis and the secondary side is situated in a vehicleseat. The device according to the present invention is then particularlywell-suited for removable seats for which wireless, in particularinductive, transmission is particularly well-suited.

It may be furthermore advantageous if a first transceiver for wirelesstransmission is situated on the primary side and is connected to the twoprocessors situated on the primary side, and on the secondary side afirst transceiver block having a first processor is connected to a firstterminal of a triggering element and a second transceiver block having asecond processor is connected to a second terminal of the triggeringelement. The transceiver is responsible for the conversion of thesignals to be transmitted with respect to frequency and amplitude. Thetwo transceiver blocks are situated on the secondary side for connectinga block to the high side and the low side of the triggering element.

It may be furthermore advantageous if the first transceiver blockreceives the redundance signal via a first winding, and the secondtransceiver block receives the deployment signal via a second winding.The first winding may be assigned to a power transmitter, and the secondwinding may be assigned to a data transmitter. As an alternative, it ispossible to use a single transmitter having two windings on thesecondary side. Electrical filtering may also be provided for separatingthe deployment signal from the enable signal.

Finally, it may be also advantageous if the first transceiver blockgenerates a supply voltage and closes the high-side switch whendeployment occurs, while the second transceiver generates and monitorsthe power reserve and closes the low-side switch when deployment occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention are illustrated in thefigures and explained in greater detail in the description that follows.

FIG. 1 shows a first block diagram of the primary side of an exampledevice according to the present invention.

FIG. 2 shows a block diagram of the secondary side of the example deviceaccording to the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

New airbag generations have a high degree of redundancy in theirelectronic systems. The microcontroller, as a processor, which performsthe analysis and executes the deployment algorithm, is also connected toa safety semiconductor, which also inputs and independently checks thesensor data. Deployment of restraining means occurs only if this safetysemiconductor also determines deployment, as long as this is alsodetected by the microcontroller. Various watchdog monitoring units andother safety structures may also be provided in the triggering circuit.

According to the present invention, the redundancy of the processors,which is achieved using the safety semiconductor and themicrocontroller, is extended to the secondary side. On the primary side,a transceiver is connected to the microcontroller and the safetysemiconductor acting as the two processors, the transceiver beingtypically connected to a secondary side via two transmitters, one datatransmitter and one power transmitter, the secondary side being situatedin the steering wheel or in a removable seat, for example. The secondaryside has a transceiver block on the high side and another transceiverblock on the low side of the triggering element. A processor, connectedto the other processor via a communication line, is situated in eachtransceiver block. Redundancy similar to that of the primary side maythus also be achieved on the secondary side by using the two processors.

FIG. 1 shows in a block diagram the primary side of the device accordingto the present invention. A transceiver ITIC is connected to amicrocontroller μC and a safety semiconductor SCON via two data inputseach. Microcontroller μC is connected to safety semiconductor SCON via aline SPI. Furthermore, a data output of microcontroller μC is alsoconnected to safety semiconductor SCON via a line ECLK. A line VZP forvoltage supply is also connected to transceiver ITIC. Transceiver ITICis connected to a power transmitter 1 via a first output and to a datatransmitter 2 via an input/output. Power transmitter 1 and datatransmitter 2 are both transformers.

Transceiver ITIC provides the voltage and frequency for powertransmission, as well as the voltage and frequency for the enable signalin the redundancy path via power transmitter 1. Furthermore, transceiverITIC contains an arrangement for data transmission via data transmitter2. Such arrangement may include, suitable drivers, for example.Microcontroller μC outputs a deployment signal F1 and diagnosis signalsF2 via transceiver ITIC. The responses to the diagnosis signals, whichare transmitted back to transceiver ITIC by the secondary side via datatransmitter 2, are then relayed to microcontroller μC, which then checksand determines the reliability performance of components, in particularof a triggering element. Safety semiconductor or safety controller SCONanalyzes sensor signals simultaneously with microcontroller μC to detecta deployment situation. If controller SCON also detects a deploymentsituation, SCON transmits an enable signal to ITIC; if the safetysemiconductor does not detect a deployment situation, controller SCONtransmits no signal or a disable signal. The signals relayed bytransceiver ITIC to the transmitter(s) are then relayed to the twosecondary-side processors for analysis.

FIG. 2 shows a block diagram representing the structure of the secondaryside of the device according to the present invention. A winding W1 ofpower transmitter 1 is connected to a transceiver block IRHS and anothertransceiver block ITLS. A winding W2 of data transmitter 2 is onlyconnected to transceiver ITLS. Transceiver IRHS is connected to a switch201 and a triggering element Z. Transceiver IRHS is connected totransceiver ITLS via a double line SPI (serial peripheral interface),i.e., a serial data line, enabling the two processors μC, situated inthe transceiver blocks, to exchange data. The two transceiver blocksIHRS and ITLS are each connected to a power source 202, here a voltagesource. Transceiver ITLS is also connected to the ignitor, specificallyto the low side, as well as to a power reserve ER, which is directlyconnected to a power IC (power semiconductor) in transceiver block ITLS.Transceiver block ITLS has a low-side switch 205, typically a transistorswitch, which is closed in the event of deployment. Transceiver blockIRHS has a high-side switch 204, which is also closed in the event ofdeployment to trigger triggering element Z, an ignitor, for example.Furthermore, transceiver block IRHS has an analyzer module 203 fordetecting switching signals of switch 201.

Redundancy for improving bidirectional communication via line SPI isachieved on both primary and secondary sides via two microcontrollersμC. Microcontroller μC in transceiver block IRHS is used for readingsteering wheel switch 201 and optionally from sensors. Furthermore, thesupply voltage is generated here by power source 202 and the powertransmitter, and high-side switch 204 is closed in the event ofdeployment. The power reserve in capacitor ER is generated and monitoredin transceiver ITLS by component PIC (power IC), and low-side switch 205is closed in the event of deployment. The PC in ITLS also organizes thedata transmission to the primary side via winding W2. The processor intransceiver block IRHS analyzes the enable signal which is transmittedvia winding W1. The enable signal indicates whether or not SCON hasdetermined deployment. Processor μC in transceiver block ITLS analyzesthe deployment command which is transmitted via data transmitter 2 andwinding W2. If both processors in transceiver blocks IRHS and ITLSdetermine deployment based on the signals, only then is triggeringelement Z triggered by the closing of switches 204 and 205. For thispurpose, either the power supply via winding W1 or power source 202 and,optionally, power reserve ER are used.

1-8. (canceled)
 9. A device for wireless transmission of a deploymentsignal, the device being configured to transmit the deployment signalvia a first path and a redundance signal to the deployment signal via asecond path, the device comprising: a primary side including twoprocessors configured to exchange data with one another; and a secondaryside in communication with the primary side, the secondary sideincluding two processors configured to exchange data with one another.10. The device as recited in claim 9, wherein the primary side issituated in a steering column and the secondary side is situated in thesteering wheel.
 11. The device as recited in claim 9, wherein theprimary side is situated in a vehicle chassis and the secondary side issituated in a vehicle seat.
 12. The device as recited in claim 9,wherein the primary side further includes a first transceiver configuredfor wireless transmission connected to the two processors of the primaryside, and wherein the secondary side includes a first transceiver block,the first transceiver block including a first of the two processors ofthe primary side, the first transceiver block being connected to a firstterminal of a triggering element, and wherein the secondary side furtherincludes a second transceiver block, the second transceiver blockincluding a second one of the two processors of the secondary side, thesecond transceiver block being connected to a second terminal of thetriggering element.
 13. The device as recited in claim 12, wherein thewireless transmission is configured as an inductive transmission. 14.The device as recited in claim 12, wherein the first transceiver blockis configured to receive the redundance signal via a first winding, andthe second transceiver block is configured to receive the deploymentsignal via a second winding.
 15. The device as recited in claim 14,wherein the first winding is assigned to a power transmitter, and thesecond winding is assigned to a data transmitter.
 16. The device asrecited in claim 12, wherein the first transceiver block is configuredin such a way that the first transceiver block generates a supplyvoltage and closes a high-side switch when deployment occurs, and thesecond transceiver block is configured in such a way that the secondtransceiver block generates and monitors a power reserve and closes alow-side switch when deployment occurs.